1. Field of the Invention
The field of the present application pertains to medical devices. More particularly, the field of the invention pertains to an apparatus and method for a global coordinate system for use in robotic-assisted surgery.
Embodiments described herein are directed to a new method, apparatus, and system for generating and operating a global coordinate system that may be useful for performing robotically-assisted surgery.
2. Description of the Related Art
Present microsurgical procedures are currently extremely technique dependent. For example, several existing solutions for eye surgery involve various techniques with lasers and phacoemulsification.
Modern extracapsular cataract surgery is usually performed using a microsurgical technique called phacoemulsification, whereby the cataract is emulsified with an ultrasonic hand piece and then suctioned out of the eye. Before phacoemulsification can be performed, one or more incisions are made in the eye to allow the introduction of surgical instruments. The surgeon then removes the anterior face of the capsule that contains the lens inside the eye. A phacoemulsification probe is an ultrasonic hand piece with a titanium or steel needle. The tip of the needle vibrates at ultrasonic frequency to sculpt and emulsify the cataract while a pump aspirates particles through the tip. In some techniques, a second fine steel instrument called a chopper is used from a side port to help with chopping the nucleus into smaller pieces. The cataract is usually broken into numerous pieces and each piece is emulsified and aspirated out with suction. The nucleus emulsification makes it easier to aspirate the particles. After removing all hard central lens nucleus with phacoemulsification, the softer outer lens cortex is removed with suction only. As with other cataract extraction procedures, an intraocular lens implant (IOL), is placed into the remaining lens capsule.
One possible improvement to phacoemulsification is a cataract surgery performed with lasers. Femtosecond laser cataract surgery is rapidly emerging as a potential technology that may allow for improved precision of incision formation and emulsification of the cataract. Although phacoemulsification and laser-based cataract surgery work well for many patients, these technologies have several shortcomings. For example, phacoemulsification ultrasound probes must propagate ultrasound energy along the length of the probe, from a proximal transducer to a distal tip. This propagation may lead to transmission of ultrasound energy along the probe to tissues in and around the eye that do not benefit from the transmission. Current lens emulsifying probes generate cavitation energy that is initiated within the area of lens nucleus and radiates outwards towards the lens capsule. This places the lens capsule at risk for damage by this energy. Ultrasound probes also tend to generate more heat than would be desirable for a procedure in the eye.
Finally, it may be quite difficult to steer an ultrasound probe around corners or bends, due to the mechanical requirements of propagating the ultrasound wave along the entire instrument. In other words, the probe may have to be rigid or at least more rigid than would be desirable.
Probe based lasers have similar drawbacks. They may generate unwanted heat in the eye and are often difficult to control, thus risking damage to important nearby tissues. They also are easily damaged when attempting to navigate tight corners, as fibers in a laser probe may easily break.
Femtosecond laser systems have been devised to assist in the removal of cataracts. These devices are used to create the entry sites through the cornea and sclera into the eye, as well as to remove the anterior face of the capsule. In addition, the femtosecond laser energy can be focused within the lens nucleus itself, and used to “pre-chop” the lens nucleus into a number of pieces that can then be more easily removed with the phacoemulsification probe. However, these lasers can only fragment the center zone of the lens that is visible within the pupil (the iris blocks the peripheral lens from laser energy), so that fracture and removal of the peripheral lens by another method is still necessary. They are costly to own and operate and have the additional drawback of extending operative time.
The aforementioned techniques require extreme precision for successfully completion and minimal complications. Therefore, it would be beneficial to have an apparatus and method for a global coordinate system for assisting performing surgery for various applications including eye, micro-surgery, and/or other emulsification applications.